Aden is the UK's AY-d@n and US's AH-den. It is located near the Red Sea (the Gulf of Aden) at 170 km (110 miles) east of Bab-el-Mandeb. The city is home to approximately 800,000. Aden's natural harbour is located in the crater a dormant volcano. It now forms a peninsula that connects to the mainland via a low isthmus. Front Bay was the first harbour to be used by the ancient Kingdom, Awsan, between the 7th and 5th centuries BC. On the opposite side of the peninsula is the modern harbour. The Gulf of Aden is named after Aden.
Aden is made up of several sub-centres. Crater was the original port city. Maalla was the modern port. Tawahi, also known as Steamer Point during colonial times, and the resorts at Gold Mohur are all part of the main centre. Khormaksar is located on the isthmus connecting Aden with the mainland. It houses the city's diplomatic missions and the main offices for Aden University. Aden International Airport, which was formerly the British Royal Air Force station RAF Khormaksar (Yemens second largest airport), is also here. The sub-centres and Al-Mansura are located on the mainland. These were once an oasis area. Madinat ash-Shab, formerly Madinat al-Itihad, is now the capital of South Arabian Federation. It also houses Aden University's large power/desalinization plant and additional faculties.
Aden surrounds the eastern end of the vast, natural harbour that forms the modern port. This made it necessary to create the Cisterns at Tawila, Aden's reservoirs.
Taipei (), officially Taipei City, is the capital and a special municipality of Taiwan (officially the Republic of China, ROC). Located in northern Taiwan, Taipei City is an enclave of the municipality of New Taipei City that sits about 25 km (16 mi) southwest of the northern port city of Keelung. Most of the city lies on the Taipei Basin, an ancient lakebed. The basin is bounded by the relatively narrow valleys of the Keelung and Xindian rivers, which join to form the Tamsui River along the city's western border.The city proper is home to an estimated population of 2,646,204 (2019), forming the core part of the Taipei–Keelung metropolitan area, which includes the nearby cities of New Taipei and Keelung with a population of 7,047,559, the 40th most-populous urban area in the world—roughly one-third of Taiwanese citizens live in the metro district. The name "Taipei" can refer either to the whole metropolitan area or the city proper.
Taipei is the political, economic, educational, and cultural center of Taiwan and one of the major hubs in East Asia. Considered to be a global city and rated as an Alpha - City by GaWC, Taipei is part of a major high-tech industrial area.